Sound-recording apparatus.



T. A. nmso'n. SOUND RECORDING APPARATUS. v APPLIOL'HOI nun APP-.20, mo.4 1,019,441. 'Pa tented Mar.5, 1912.

gYw/J'JK I ygw lfl w Recording STATES, PATENT OFFICE.

x imrson, or mwnLI-im rank, was-r omen, msw mnsnr, assumes or wssr omen,new masnx, a coa- IO mom A. EDISON, INCORPORATED,

tomato! 0] m sommsconnms arrana'rus.

Specification of Letters Patent.

- Application filed April 20, 1910. Serial Ito. 556,469.

' Patented Mar. 5, 1912.

To all whom it may concem:

Be it known that I, Tnoms A. Emson, a citizen of the United States, anda resident of Llewellyn Park, West Orange, Essex county, NewJersey,-have invented certain new and useful Improvements in Soundin isa escription. v

y invention relates to devices for recordsound, and my objectsaretheprovision b f a novel and eflicient sound recorder ofsuficientsensitiveness to respond to sound waves of little power, and atthe same time so constructed as to lar y prevent excessive movement ofthe diap ragm and recordin stylus in' a direction away from the recoring surface under the influence of sound waves of great amplitude. Myimproved apparatus therefore is intended to record than has heretoforebeen sounds, both weak and strong,lmore truly slb e. a In order that afull un' erstanding of my .4 invention may be had, attention is herebydirected to the accompaing drawings forming cation, and In part ofthis'spec which Figure 1 re resentsavertical central cross sectionthroug a sound recorder embodying oneform of my invention. Fig. 2 is abot? tom plan viewthereof; Fig. 3 1s a sectional detai view showing thepreferred manner of mounting the diaphragm; and Fig. 4 is a similar viewshowing a modified mounting thro s for the diaphragm.

The same reference characters will be used bout to denote correspondingRe to the drawings, the-soun box 1 is provided with a recess 2 toreceive and guide the diaphragm. The latter consists ,40

- -nular or ring sha of a flexible outer. ortion preferabl anas shown at3 111 the drawingsh and an inner non-flexible portion 4. The exible 3which may consist of glass, or ot r suitable material, is

m out touching the sides of the same, and is sup rted preferably b knifeed 5 exten downwardly rom soun box 1 within recess 2, said knife edgebeing sitioned to engage the upper surface 0 the flexible ri 3 adjacentto the outer ed thereof. l he ring 3 is not secured to t e I sound. boxby wax, rubber, or in any other Apparatus, of which the follow arts.

in recess 2 of sound box 1 withyielding otherw se to its upper sideadjacent the outer edge to form a bearing surface for way as is usual inthe art. The rigid or nonflexible portion 4 of the diaphragm is giventhe form of an arch, as shown, or is. formed in any other Way so that itwill not be flexed by the pulsations of the sound waves upon it. Thisrigid member 4 of the diaphra m is preferably circular in form with itse ge bent sharply upward, as shown at- 6, and forming a knife edgecontacting the lower side of the flexible ring 3 near the inner,

edge thereof. The recording stylus 7 is carried by spring lever 8, theother. end of which is flattened and secured within the sound box byscrew 9.

. In assembling the recorder the ring mem- V ber 3 of the diaphragm isplaced upon knife edge 5, being guided and located by theedge of recess2 of sound box 1, and the non-flexing member 4 of the diaphragm is thenplaced in position with its shar peripheral edge 6 cont-acting the undersi e of ring 3 near its inner edge. A rigid connectlon 10'is thenplaced. between the end of s ring member 8 and the center of the rigidiaphragm member 4, the spring member 8 being given a strong inwardflexure and the connecting member 10 then firmly secured, preferably byshellac, at its two ends to the diaphragm member4 and the spring member8. Screw 11 may be mounted as shown in shoulder-12 of the sound box withits ends contactin the under side of spring member 8, where y the.amount of flexure of spring member Smaybe adjusted.

Lever 13 carr ing tracking. member 14 may be used if esired, the screw15 being mounted in the sound. box' with its lower ,end'bearing upon theupper side of the free end of lever 13- to adjust the vertical posi tionof tracking member 14 to regulate the depth of out permissible" forrecording stylus 7.

In Fi in whic rin member 3 of the diaphra is provided with a ring ofrubber or simi ar material 16 securedby cement or knife edge 5 of thesound box, and a similar edge 6 of the rigi imember 4- off'tlie.,d1aphragm.' This con- 9.5 4 I have illustrated a modification Iconnection with t struction is to permit the use of such material forflexible ring 3 as cannot be entirely freed of buckling'around theedges, but I prefer to form the ring 3 ofmaterial free from buckles andto have knife edge 5 of the sound box and edge 6 of the ri d member 4bear directly upon the flexi le ring as shown inv Fig. 3. The screw 11pressing u on spring 8 bows the latter inwardly an forces the diaphragmupwardly sufliciently to give a strong initial upward tension to thelatter.

The following points may e diaphragm constructed as above describedFirst: Less power is consumed in vibrating itthan in the case ofdiaphragms secured to the sound box by wax, rubber, or

similar substance attached to the outer edge of the diaphragm, as hasbeen the common practice heretofore, since power has necessarilybeen'lost in stressing this securing device. Accordingly, my dlaphragmis more sensitive.

Second: Less strength is required in a sound wave to be recorded to movethe diaphragm a given distance than in the common recorder construction,since it does not flex in the center; The ring '3 is easily flexedbecause of itsfree inner edge. 4

Third: The diaphragm does not buckle in segments within the limits ofthe deflecs tions given by the sound waves to be, recorded. Fourth: Byemploying a non-flexing center and a flexible ring diaphragm free atboth edges, a strong upward stress can be given the whole diaphragm,which not only serves to hold it 1n place, but also strongly resistsexcessive movement of the diaphragm ifu a directionaway fromtherecording surace. 7 y

' When the recording stylus is tracked for the record, the movement ofthe diaphragm downward or toward the recordin requires but little power,but the on upper movement of the same is ard or atl reslsted by thestrong initial flexing o the dia hragm which has been described. Accoringly, the tendency of strong sound waves or waves oflarge amplitude tocause the recording stylus to leave the record material is stron 1yresisted. With the form of diaphragm eretofore used in recorders, theinitial flexing necessa of false motions given ,to the diaphragm whichare recorded with suflicient amplitude to be audible in the record whenreproduced. In the construction which l have-described and illustrated,however, no false'motions of'sufiicient amplitude to be audible on re--.production are given tolthe diaphragm.

It is to be understood that my invention is not limited to the exactconstruction above be noted in bination with a sound surface toe-amuleeflect described is not practicable on account described, but isas broad, as the appended claims.

Having now described my invention,

-what I claim and desire toprotect by Lettors Patent is: l 1. In soundrecordin apparatus, the combination with a flexi le ring dlaphra and anon-flexible central member bridging the opening .of the ring and incontact therewith, of a recording stylus connected to the non-flexiblemember, and means for a'pplyingan elastic the flexible an non-flexiblemembers in engagement, substantially as described.

2. In sound recording apparatus, the combination of a lmife edge suport, a twogressure on the stylus toholdpart diaphragm, comprising aexible ring member freely mounted on said support with the lattercontacting the same ad acent to one edge thereof, and a non-flexiblememher-bridging the opening of said ring and making contact therewithnear the .other edge thereof, a recording stylus and a spring armcarrying the stylus and by its tension imposing an initial flexure onthe diaphragm to keep the parts thereof in en- -ga ement and the ringmember seatedon sa1 knife jedge, substantially as described.

3. In sound recordin apparatus, the combination with a soun box, of aflexible ring diaphra mounted therein, a nonflexible mem er. mounted tocontact the inner edge of saidring but not attached thereto, and arecordin stylus connectedto said non-flexible mem r, substantially asdescribed.

4. In sound recordin apparatus, the commounted therein comprising aflexib e outer portion and a'rigid inner ortion, the outer edge of whichcontacts t e inner edge of the flexible outer portion but is notattached thereto, and a recording stylus rigidly connected to said rigidinner portion of the diaphragm, substantially as described.

5. In sound recording ap aratus, the com-' bination with a supportingife edge, of a ox, of a diaphragmdiaphra m comprising a flexible ringmounte with its'surface adjacent its outer edge contacting said knifeedge, a nonflexible member mounted with its outeredge contacting thefree inneredge, of said ring but not attached thereto, and a recordingstylus connected to said non-flexible member, substantially asdescribed.-

' 6. In sound recording apparatus,the

bination witha knife-edge support, of" a flexible annular diaphra ucontactmgmd support near the outer w 1 of thcannulus, and free atbothjedges a non-flexible member the. outer of" istral. r and connectedto said non meansfor holding said member in firm 0012- edgewhichcontacts the j inner edge of sai annulus -on the side optact withsaid annulus and placing the latter under initial upward stress,substantially as described.

- 7. In a device of the class described, the combination with :1; stlus, of a diaphragm connected thereto an comprising a rigid inner ortionand a flexible outer portlon combination with a stylus of a diaphragmconnected thereto comprising a'ri'gid inner port1on and a flexible outerportion mount-, ed to vibrate therewith and having a free inner edge andmaintained under initial upma PatentNc. 1.019.441.v

ward tension, substantiall as described.

9. In a device of the c ass described the combination with a st lus, ofadiaphragm connected thereto an comprising a rigid inner portion and aflexible outer portion adapted to vibrate with said inner portion butnot secured thereto, a knife ed e con-- tacting the outer upper surfaceof t e said outer portion, and means for lacing the diaphragm underinitial'upwar stress, substantially as described.

10. In sound recording apparatus, the.

combination with a recording stylus of a connected thereto comprisinga rgidlnner portion and a flexible outer portlo'ni alkmfe edge contactingthe outer upper of the latter and constituting the" Patent signed an mamldayot April, Lin, 1 12,

only support therefor, said inner portion having a sharp outer edgecontacting the under side of the outer portion near the inner edgethereof but not'joined thereto,

and elastic means for holding the inner ortion in contact with the outerortion o the diaphragm, substantially as escribed.

11. In a device of the class described, the combination with a sound boxof a flexible diaphragm member inounted therein but not secured thereto,and having free edges, a non-flexible diaphragm member mounted :tovibrate therewith, and a stylus connected thereto, substantiall asdescribed.

12. In a device 0 the class described, the combination with a sound boxof a flexible annular diaphragm member mounted therein but-not securedthereto, and having free edges, a support for said flexible member adacent its edge, and a stylus connected to vibrate with said diaphragmmember, substantia'llyas describe 13. As a new article of manufacture,an.

inner non-flexible diaphragm member, provided with a sharpen'ed edge forcontact with a flexible annular diaphragm member, substantially asdescribed;

This ecification signed witnessed this 14th day of April 1910.

THOMAS A. EDISON.

Witnesses: Possum. Eeemcs'ron,

'. A. N. Prsnmn.

in is hereby certified a r am No.- 1,019,441, ad-inlet a, 1912, upon theapplication 6: 11.15am, bf Llewellyn; Park, as Orange,

New Jersey, for an improvement in Sound- Beeording Apparatus, an errorin the printed specification requiring'correction as follows: Page 1,line 85, for the word ends that the said Letters Patent should be readwith this correction therein that alanin may conform to the record ofthe case in the c. c. sun-mes, Acting of tact with said annulus andplacing the latter under initial upward stress, substantially asdescribed.

- 7. In a device of the class described, the combination with :1; stlus, of a diaphragm connected thereto an comprising a rigid inner ortionand a flexible outer portlon combination with a stylus of a diaphragmconnected thereto comprising a'ri'gid inner port1on and a flexible outerportion mount-, ed to vibrate therewith and having a free inner edge andmaintained under initial upma PatentNc. 1.019.441.v

ward tension, substantiall as described.

9. In a device of the c ass described the combination with a st lus, ofadiaphragm connected thereto an comprising a rigid inner portion and aflexible outer portion adapted to vibrate with said inner portion butnot secured thereto, a knife ed e con-- tacting the outer upper surfaceof t e said outer portion, and means for lacing the diaphragm underinitial'upwar stress, substantially as described.

10. In sound recording apparatus, the.

combination with a recording stylus of a connected thereto comprisinga rgidlnner portion and a flexible outer portlo'ni alkmfe edge contactingthe outer upper of the latter and constituting the" Patent signed an mamldayot April, Lin, 1 12,

only support therefor, said inner portion having a sharp outer edgecontacting the under side of the outer portion near the inner edgethereof but not'joined thereto,

and elastic means for holding the inner ortion in contact with the outerortion o the diaphragm, substantially as escribed.

11. In a device of the class described, the combination with a sound boxof a flexible diaphragm member inounted therein but not secured thereto,and having free edges, a non-flexible diaphragm member mounted :tovibrate therewith, and a stylus connected thereto, substantiall asdescribed.

12. In a device 0 the class described, the combination with a sound boxof a flexible annular diaphragm member mounted therein but-not securedthereto, and having free edges, a support for said flexible member adacent its edge, and a stylus connected to vibrate with said diaphragmmember, substantia'llyas describe 13. As a new article of manufacture,an.

inner non-flexible diaphragm member, provided with a sharpen'ed edge forcontact with a flexible annular diaphragm member, substantially asdescribed;

This ecification signed witnessed this 14th day of April 1910.

THOMAS A. EDISON.

Witnesses: Possum. Eeemcs'ron,

'. A. N. Prsnmn.

in is hereby certified a r am No.- 1,019,441, ad-inlet a, 1912, upon theapplication 6: 11.15am, bf Llewellyn; Park, as Orange,

New Jersey, for an improvement in Sound- Beeording Apparatus, an errorin the printed specification requiring'correction as follows: Page 1,line 85, for the word ends that the said Letters Patent should be readwith this correction therein that alanin may conform to the record ofthe case in the c. c. sun-mes, Acting of Correctlori In Letters PatentNo. 1,019,441.

I: is hereby certified that "i 1mm Pm; No. 1,019,441, uted March a.1912, pon the application of Thames A. Edison, of LlewellynPark, WestOrange, New Jersey, for an inlprovement in Sound-Recording Apparatus, anerror nppeara in the printed specification requiring correction asfollows: Page 1, 11085, for the word endu reed end; and that the saidLetters Potent should be read with this correction therein that the samemay conform to the record of the case in the Patent Signed and sealedthis 2nd day of April, A. 1)., 1912.

[ 0. c. mnmuos,

Acting of Patente.

